dillon1000/react

Allow eslint rule reportable severity to be set

During the demo I might show an example of fixing a
CannotPreserveMemoization error. But I don't want to make that
reportable by default, so this PR allows configuration like so

```js
module.exports = {
  root: true,
  plugins: [
    'eslint-plugin-react-compiler',
  ],
  rules: {
    'react-compiler/react-compiler': [
      'error', {
        reportableLevels: new Set([
          'InvalidJs',
          'InvalidReact',
          'CannotPreserveMemoization'
        ])
      }
     ]
  }
}
```

ghstack-source-id: 984c6d3cb7e19c8fea2bb88108dd26335c031573
Pull Request resolved: https://github.com/facebook/react-forget/pull/2936